Latch



April 28, 1931. F, Ei BESSLER 1,802,401

LATCH Filed Aug. 4 1928 2 Sheets-Sheet l WSWS il' gmc/wind',

April 28, 1931. E. E BESSLER 1,802,401

LATCH Filed Aug. 4 1928 2 SheetsfSheet 2 atto/mago@ Patented Apr. 28, 1931 UNIT-ED STATI-:fs PATENT sorrise FRANK E. `BESSLER, F AKRON,Y lOI-III() LATCH i Application :tiled August 4,V 1928. Serial 110.297,544.`

rrrlh'e 'device forming '.the .subject matter 4of Lthis "application Sis a latch, adapted' te be used primarily "in 'connection with a stair- ,way which slides on a A'hingedly 'mounted panel, the llatch being intendedfor the protecti'on"oi theop'erator of `the stairway in that it prevents the same from 'sliding back V'to the floor 'after fit has 'once been started 'back toits ino'perativ'e position. The Ainvention :aims Y't'o'provide a "latch of Ithe class 'described lvshichvrill "be 'partially automatic in its act/ion, and require` noattention "onthe part of 'the 'operator other Vxthan comes from 'sliding the 's'tairway 'on the panel.

"tofirnprove generally and -to enhancelthe 'utility "of "devices .di that 'type 'to which the invention' appert'ains. y

With therabove Vand other 'objects in view,

270 which 'appear as the description proceeds, 'the invention resides yin the combina- ;ti'on, :and v'arrangement of'V parts and in the details "of construction hereinafter described "and claimed, it being understood that i 25 `Changes in the precise embodiment of the 'invention herein disclosed, may 'berna'de within'thescopeV of What vis claimed, without ldeparting from `the "spirit 'of fthe invention. Intheaccompany'ing drawings ,y

`Figure v1 'shows inside elevation. a latch constructed in accordance with the in'ven tion, mount'edlon a stairway which has vbeen lowered with respect "to a panel;

Figure f2 4is an elevation showing `the parts 35 -a's they 'will appear after the stairway has as "they 'will appear-'after the stairway `and fi-'iin the panel have been-*completely raised;

jIt is within the province ofthe disclosure f Figure v6 is 'a transverse section on the line 6-'6 'ofFigure 5; y Y

In order that one application of the 'invention may be understood clearly, it lisfr necessaryjto describe apart 'of the s'triicture i' on which the latch formin'gthe subject matter of this application has 'been mounted.

The numeral 1 marks a support, which maybe the ceiling of a room, thev sujpport/ 1 having an opening.A The numera'l'des# ignates apanel mounted ,to swingvertical'ly, thefpan'el 3 being hinged `at Lon'eend to the Vsupport 1, as vshown at 4; Vl`he.panel 3 constitutes a Vclosure for fthe"` opening 2. -The panel may be swungdownwardly into the'.- position shownin Figure 1, by `means of aV chain 22 or 'the like, attached to lthe 'lower endo'f the panel. 'On the support 1 'a't one Vend of the opening j`2fthere 'is a hanger 5 on which a spring vactuated drum 6 is journaled. On the lower end 'ofthe ypanel i3 there'ris a bracket 7` r*carrying a wheel "8.

A stairway Slis slidably supported'at its lupper end on the hanger 5, and 'at itslower r end on the wheel 8. The""stairway f5)v has longitudinal -guidegrooves 10 Vin 4its sides. In the bracket 7 there is a rivet 11 which k.holds the block 12 that lis v`receivedslid'alil'y in. the guide groove 10 of thestaiiway '9. So far `as the present 'invention is concerned, attention is `directed only 'to the jouter end ofthe rivet 11 which'fforrns afprojecti'on 121. AA flexible elem'ent is connected 'to Ythe spring actuated drum 6. The flexible element 15 passes a guide gpulley supported i for rotation on the "member 1 near tothe opening 2. The nlower end of the flexible element is connected to a fran/ie 17car`rying the wheel 18 which has` a limited sliding movement, lengthwise :of the panel '3, on a track 19 which is secured to gthe lq oan'el. Because the wheel 18 can slide along the track 19, 'the iie'xible lelement 15 'has 'an increased mechanical advantage in fthewvay of an upward pull on the panel 3 as theI panel swings upnf'ardly 'toward closed position. vFigure lis -an 'elevation showing the parts The numeral marks 1a vflexible element connected to the spring actuated-drum 6 and, f

vadapted to bei wound-thereon. rThe flexible element 20 extends lengthwise of the stairway 9 and is anchored at one end as shown at 21 to the stairway. The flexible element 20 is adapted to be put under tension by the vs ring actuated drum 6, and has a part in t e opera-tion of the latch which will be descri ed hereinafter.

No novelty is claimed for the parts hereinbefoie set forth, saving in so far as they may enter into combination with parts hereinafter specified. In operating the stairway, the panel 3 is swung down by means of the chain 22 and the stairway 9 slides or is drawn down to the position shown in Figure 1. When the operator desires to Stow the stairway 9, he pushes it back on the anel 3, the fiexible element 2O aiding in the backward movement of the stairway 9. When the stairway 9 has been pushed back far enough, a little upward shove will close the panel 3, especially in view of the fact that the flexible element 15 exerts an upward pull on the panel. lVitli such a structure, or with an equivalent device, the latch forming the subject matter of this application is adapted to be used.

An anchor plate 23 is secured to the stairway 9 near to the lower end of the stairway. The numeral 24 marks a U-shaped latch which is pivotally mounted at 25, at a point near to one end of the latch, to swing on'the anchor plate 23. The pivotal mounting of the latch 24 at 25 is of such nature that some force lnust be applied to the latch in order to move it. The latch does not swing freely on the pivot 25. At one end the latch 24 has a hook or seat 26. The latch 24 has an internal cam 51 leading to the seat 2G. The end of the latch which is adjacent to the hook is rounded as shown at 27, and the latch has a straight edge 29 which extends from the rounded edge 27 to the bill of the hook 26. The edge 29 may be referred to as a first operating surface. r.that end of the latch which is opposite to the rounded end 27 has a lever arm 2S. The lever arm 28 has a second operating surface Intermediate its ends, the latch 24 has a laterally projecting trough shaped bracket 3() from which projects an arcuate detent 31. The lower portion of the bracket 30 constitutes an actuating surface 52.

Suppose that the panel 3 has been raised to a c osed position, as shown in Figure 5, and that thc spring actuated drum (i is cxerting a pull on the flexible element 20, so that the stairway 9 tends to move to the left in Figure 5, thereby engaging the detent 31 with the projection 14.

The planel 3 s swung down into the position s own in Figure 3, for instance. The first thing that occurs, as the stairway starts to move downwardly on the inclined panel 3 is that the edge 29 of the latch 24 comes into contact with the projection 14. This tilts the latch 24 on its pivotal mounting 25, and the projection 14 passes along the edge 29 of the latch 24. The latch thus appears in Figure 1 of the drawings, wherein the stairway 9 has been pulled down as far as it will go.

When the operator shoves the stairway 9 upwardly on the panel 3, the projection 14 comes into contact with the inner edge 50 of the lever arm 28, the detent 31 passing above the projection 14, and the projection arriving in the position shown in Figure 3 of the drawings. The stairway 9 now gravitates down hill a little, and the projection 14 arrives in the hook 26 of the latch 24, the construction being such that the stairway 9 cannot slide back upon the operator during the upward movement of the stairway and the panel.

When the panel 3 arrives at a horizontal or closed position, as shown in Figure 5, the flexible element 20 exerts a pull on the stairway 9 and slides the stairway 9 to the left in Figure 5, until the projection 14 is engaged with the detent 31. The parts arennow in position to repeat the cycle hereinbefore described.

Owing to the somewhat complicated operation of the latch 24, that operation posslbly will be better understood if confined to the latch 24 and the projection 14, without reard to the specific mechanism employed or mounting and operating the stairway 9. It may therefore be stated that the projection 14 and the latch 24 are mounted for relative backward and forward movement, as shown by the arrows of Figure 5, the arrow A indicating a backward movement, and the arrow B indicating a forward movement. Referring to Figure 5, upon a firstforward movement of the latch 24 in the direction of the arrow B, with respect to the projection 14, the projection will engage the first internal operating surface 29 and tilt the latch 24, to move the detent 31 upwardly and out of the path of the rojection 14, the projection 14 engaging t e second operating surface 50, upon a backward movement in the direction of the arrow A.,

to tilt the latch 24 and dispose the cam 51 p in the path of the projection 14, as shown in Figure 3, the projection 14 coacting with the cam 51, upon a second forward movement in the direction of the arrow B, to tilt the latch 24 and engage the projection 14 in the seat 26, as shown in Figure 4, the projection 14 coacting with the actuating surface 52, upon a second backward movement in lthe direction of the arrow A, to direct the projection 14 into engagement with the detent 31, and to tilt the latch 24 and dispose the first operating surface 29 in the path of the projection 14, the parts thus being restored to the position of Figure 5.

What is claimed is zl. Ina device of the class described, a U-shaped latch provided at one end with a hook shaped member, the latch having an end portion located outwardly of the hooky shaped member, the latch being provided at its opposite extremity with a lever arm, an offset bracket on the inner edge of the latch, between the lever and the hook shaped member, and a detent projecting from the bracket in the same general direction as the lever.

2. A device of the class described, comprising a latch mounted for restrained pivotal movement and provided with a first internal operating surface and with a second internal operating surface located opposite to each other, the latch having an internal seat disposed inwardly of the first operating surface, the latch being provided with an internal cam leading to the seat, an internal detent mounted on the latch, the latch having an actuating surface leading to the detent, the detent and the actuating surface being located betweenthe first and second operating surfaces; a projection, and means for mounting the projection and the latch for relative backward and forward movement, whereby upon ka rst forward move ment of the latch with respect to the proj ection, the projection will engage the first'internal operatingsurface and tilt the latch, to move the detent out of the path of the projection, the projection engaging the second operating surface, upon a backward movement, to tilt the latch and dispose the cam in the path of the projection, the projection coacting with the cam,-upon a second forward movement, to tilt the latch and 40 engage the projection in the seat, the projection coacting with the actuating surface, upon a second backward movement, to direct the projection into engagement with the detent, and to tilt the latch and dispose the l5 first'operating surface in the path of the projection.

c In testimony that I claim the foregoing as my own, I have hereto aiixed my signature. Y

5o FRANK E. BESSLER. 

